Silk screen printing machine



May 21, 1963 L. e. DUBUIT SILK SCREEN PRINTING MACHINE 4 Sheets-Sheet 1 Filed Feb. 15, 1961 HHHI HI l I I l I I I I I I IUHNH I l l I v I I May 21, 1963 L. G. DUBUIT 3,090,300

SILK SCREEN PRINTING MACHINE Filed Feb. 15, 1961 4 Sheets-Sheet 2 TN 12' W2 3 I I k 1 a 1 S MV May 21, 1963 L. G. DUBUIT 3,090,300

SILK SCREEN PRINTING MACHINE Filed Feb. 15, 1961 4 Sheets-Sheet 4 lmw-JLW 5M; 0 x13 "Mimi States atent 3,090,300 SILK SCREEN PRINTING MACHINE Louis Gilbert Dubuit, 60 Rue Vitruve, Paris, France Filed Feb. 15, 1961, Ser. No. 102,331 Claims priority, application France Feb. 23, 1960 6 Claims. (Cl. 101123) This invention relates to printing machines, and more specifically to silk screen machines for printing on the surfaces of articles of various character.

In the silk screen printing process to which the invention relates, a printing fluid, e.g. ink, is transferred to the printing surface of the article or work by means of a transfer member or squeegee, through a stencil screen made of silk or other suitable fabric. Depending on the particular configuration of the work surface to be printed on, e.g. whether it is a flat continuous surface, a fiat annular surface, a cylindrical surface, a conical surface, or a surface of some other shape, the printing process must involve different types of relative displacements between the printing surface, the screen and the squeegee. Thus for example in the case of a fiat continuous printing surface the printing surface and the screen are generally both held in stationary engagement with each other during a printing operation and the squeegee is moved across the screen to perform its ink transferring function; in the case of a fiat annular printing surface, said surface and the screen may again be held stationary but the squeegee is subjected to a rotational displacement about an axis perpendicular to that of the screen so as to sweep the screen over an annular path corresponding to that of the surface to be printed. With cylindrical printing surfaces, the cylindrical surface is rotated about its axis While the screen is moved linearly in synchronism with said rotation so as to present different areas of the silk-screen into engagement with corresponding areas of the printing surface, while the transfer member is in this case held stationary along the contact generatrix of the cylindrical printing surface and the screen. Other types of silk-screen printing work may involve yet other types of relative displacements between the machine components.

Thus it will be apparent that the provision of a silk screen printing machine adapted to work upon differently shaped articles and satisfactorily performing the various kinds of relative motions between its components as required in connection with each individual type of work, poses complex mechanical problems.

It is an object of this invention to provide a silk-screen printing machine of high output rate and largely automatic, or semi-automatic design. Another object is to provide a pattern printing machine of great versatility in that it can be made to deal successfully with printing work of widely diversified geometrical configurations, by performing simple adjustments and/or mounting suitable attachments to the basic machine.

A more specific object is to provide such a machine which can be easily and quickly fitted out to perform continuous prints on flat surfaces, annular prints on fiat annular surfaces, prints on cylindrical surfaces, prints on conical surfaces, and prints on continuously fed bands or tapes of flexible or semi-rigid materials.

It is also a specific object to provide in a silk screen printing machine improved means, in the general form of deformable parallel linkage, for supporting the stencil silk-screen and the ink transfer member or squeegee in proper operative relationship while permitting desired relative movements to be imparted to said screen and squeegee with respect to one another and to a printing surface, in a desirably automatic or semi-automatic manner.

The above and further objects are attained in accordance with one important aspect of the invention, by the provision of a silk-screen printing machine comprising a frame; a pair of parallel-spaced shafts and deformable parallel-linkage means mounting said shafts on the frame for "bodily parallel displacement of both shafts over circumferential paths transverse to said shafts toward and away from a printing surface supported on the frame, when said linkage is deformed; a first support mounting a silk screen and supported for longitudinal reciprocation along said shafts and for bodily transverse parallel displacement bodily therewith toward and away from said printing surface; a second support mounting a printing fluid-transfer member and supported for longitudinal reciprocation along said shafts independently of said first support and for transverse displacement toward and away from said printing surface on deformation of said linkage; driver means reciprocable longitudinally of the frame; displaceable coupling means for selectively coupling the driver with either of said first and second supports for reciprocat-ing either one of said screen and transfer member, while the other is held stationary, during a printing operation; and means connected for operation by said driver for deforming said linkage on completion of a printing operation to lift both said screen and member off said printing surface.

The invention will now be described for purposes of detailed illustration but not of limitation with reference to the accompanying drawings, wherein:

FIG. 1 shows the essential part of the machine as seen in front elevation and fitted out for printing on cylindrical bodies;

FIG. 2 shows the machine in plan;

FIG. 2a shows the spring pressed plunger for connecting the stirrup;

FIG. 3 is a section on line III-III of FIG. 2;

FIG. 4 is a section on line 1V-IV of FIG. 2;

FIG. 5 is a similar section to that of FIG. 3 the machine being fitted out for applying circular prints on flat surfaces;

FIG. 6 shows the machine thus fitted out in plan.

The machine comprises a table or bed 1 having secured to both end sides thereof vertical brackets 2 and 2' provided with hearing apertures 3, 3, 4 and 4'. Mounted in the bearing apertures 3 and 3' of the two brackets are ballor needle-bearings in which is journaled a horizontal shaft 5. In the bearing apertures 4 and 4', the axes of which are aligned in a common vertical plane with the axes of the bearings 3 and 3', are fixedly secured the ends of a horizontal unrotatable guide shaft 6 parallel to shaft 5.

Keyed on the rotatable upper shaft 5 are two arms 7 and 7' and freely pivoted on the lower shaft 6 are two further arms 8 and 8'.

The arms 7 and 7 carry a horizontal shaft 9 and the arms 8 and 8' carry another horizontal shaft 10.

It may at once be seen that a double pivoted parallelogrammatic linkage system is provided comprised of the pivotal upper rear shaft 5, the stationary lower rear shaft 6, the upper front shaft 9, the lower front shaft 10, the above mentioned arms 7, 7 and 8, 8, respectively, and the rods 11 and 11' articulated to and connecting the said shafts 9 and 10; these shafts 9 and 10 will thus describe circular arcs around the axes of the shafts 5 and 6 respectively while remaining continually in a common vertical plane when the shaft 5 is pivoted in its bearings.

The vertical tie rods 11 and 11' are provided with smooth or antifriction sliding bearings 12, 12' whereby they are enabled to slide along the shafts 9 and 10 and further with horizontal fitting surfaces 13, 13', to which a flat cross bar 15 is secured with screws 14, 14' for supporting the frame 16 carrying the silk screen 17 (FIGS.

and 4).

Mounted on the stationary shaft 6 by means of antifriction sliding bearings 18 is a driver carriage 19 consisting of a hollow pylindrical body 19' which encloses said bearings 18 and is provided with a vertical flange 20 the rear face of which has secured to it or formed on it a pair of vertical slideways 21, 21. Formed in the bed 1 is a longitudinal groove '22 (FIGS. 3 and 4) adapted to receive and to guide a roller 23 mounted on a pivot 24 carried by a lug 25 secured to the base of flange 29. It is apparent that said carriage 19 is very freely slidable along shaft 6 with its flange 26 always remaining in vertical position.

A recipr-ocatory sliding movement is imparted to the carriage 19 by a roller 26 moving in the said vertical slideways 21, 21' and carried on a pivot 27 extending through a radial slot 28 formed in a crank disc 29, the slot allowing the eccentric throw of pivot 27 from the axis of the disc to be modified. Said disc is secured on the output shaft 30 of a speed reducer 31 the input shaft 32 of which is driven by an electric motor 33. The shaft 30 carrying the disc 2? might, however, be driven by any other manual or mechanical means.

Freelyvpivoted on the end portions of the cylindrical body 19' of the carriage 19 are the arms of a substantially U-shaped stirrup member 34, each arm being provided with smooth or antifriction bearings 35, 35. The stirrup 34 carries a flat spur 36 containing an oblong hole 37 (FIG. 4).

The stirrup 34 carried by the drive carriage 19 of the machine makes it possible to use the machine, selectively, either for printing on flat articles or printing on cylindrical articles, as will be described hereinafter.

As above mentioned for printing upon flat articles the silk screenshould remain in stationary position over the article and the squeegee should be reciprocated across the screen. For printing on cylindrical articles conversely the squeegee should remain stationary and the silk screen should be displaced transversely with respect to the scraper.

To satisfy either of the above conditions, the squeegee is carried by an angular support bent at right angles which includes a horizontal arm 3% terminating in sleeves 39 and 40 embracing smooth or antifriction bearings (FIGS. 2 and 3) for sliding displacement along the shafts 5 and 9 respectively and a vertical arm 4-1 on which is secured, by means of screws or bolts 42, a horizontal bar 43 holding the squeegee-carrier 44 in any suitable manner.

Moreover, the sleeve 39 sliding on shaft 5 is extended downwardly by a vertically-depending clevis or fork 45 in which the spur 36 of the stirrup 34 engages when brought into vertical position as shown in dotted lines in FIG. 3 and in full lines in FIG. 5. The clevis 45 is provided with a boss 46 in which a plunger, preferably spring-pressed and extending through the oblong hole 37 of spur 36, engages for maintaining the spur firmly connected with the arm 38 of stirrup 34 and consequently with the carriage 19.

Furthermore, a similar clevis 47 is arranged upon a bracket member 48 secured by means of screws 49 to the cross bar 15 carrying the screen-carrier frame 16. The clevis 47 is provided with a boss 50 through which extends a spring-pressed plunger 51. The bracket member 43 is so dimensioned that the spur 36 of stirrup 34 engages the clevis 4'7 when the stirrup 34 is moved to the horizontal position shown into full lines in FIGS. 2 and 3. The screen-carrying frame 16 can thus be operatively connected with the carriage 19' to impart to screen 17 a rectilinear reciprocatory movement.

To block either the squeegee or the screen Whichever is movable against displacement, two retaining rings 52 and 52 are slidably positioned on shaft 3 and securable thereto by screws 53, 53. The sleeve 48 of arm 38 of the angular squeegee-carrier may be arrested between 4 the secured retaining rings 52 and 52' as shown in full lines in FIG. 1.

Regardless of the desired type of print, it is necessary that the screen and the squeegee should be lifted off every time the carriage 19 reaches the end of its stroke. For that purpose the crank disc 29 is provided with one or two ramps or camways 29a, 2% adapted to act on a roller 6d mounted on a pivot 61 carried by a lever 62 journalled at one end about a pivot 63 secured to the base of bed 1. Rotatably mounted on the other end of lever 62 is a ring 64 secured to a rod 65 connected through a turnbuckle 66 to another rod 67 which termimates in another ring 68 rotatably mounted on the end of a lever 69. Said lever is secured on shaft 5 and is thus adapted to rotate the latter as well as the arms 7 and 7' which are also secured on the shaft.

It is apparent that, when camway 29a for example engages the roller 60 the latter will be urged downward with the lever 62 and this lever will pull the lever 69 thereby rotating the arms 7 and 7 and raise the shafts 9 and 10. Thus the screen-carrying frame 16 will be lifted by the arms 11 and 11' (FIG. 4) and the squeegee will be lifted by arm 4-1 (FIG. 3).

It will readily be understood from the drawing that the lifting displacement of the screen-carrying frame 16 will be smaller in amplitude than the amplitude of rotation of the squeegee about the axis of the upper, horizontal, pivotal shaft. In other words the squeegee is moved away from the object to be printed on a distance greater than that of the screen.

The number and length of thecamways 29a, 29b will determine the frequency and duration of the lifting displacement of the screen carrier 16 and the squeegee in accordance whether it is desired that printing is efiected only in one direction or in both directions of displacement of the drive carriage 19.

The length of the travel of said carriage 16 is obviously a function of the position of roller 26 on the crank disc 29 and such position can easily be modified by slidingly displacing the roller pivot 27 in the radial slot 28 of the disc.

In the foregoing only printing operations on cylindrical bodies and on fiat surfaces have been considered, but it will be evident that the machine also permits to perform circular prints on flat surfaces, prints on conical or frusto-conical surfaces, prints on strips of flexible or semi-rigid materials, and other work, provided the machine is equipped with appropriate accessories for each type of such printing operation.

It has been indicated that the angular support with arms 38 and 41 (FIG. 3) with its vertical arm 41 supports the bar 43 of the squeegee-carrier 44. Said arm 38 is arranged to perform a rotational movement about the upper, rear, horizontal shaft 5 which is rotated by the action of a lever 62 controlled by the crankor camdisc 29 of the machine. Such rotational movement is transmitted to the squeegee which is lifted off the silk screen in a circular path, which would not be suitable in the case of flat printing on circular articles or when printing on conical or frustoconical surfaces.

This is because, to accomplish such printing operations, the squeegee should not describe a rotational path about the upper horizontal pivotal shaft, but should perform a straight vertical upward displacement throughout which the parallel relationship between the screen and squeegee is at all times preserved.

To provide for such vertical displacement of the squeegee, the said horizontal arm 38 (FIGS. 5 and 7) which is slidable on the two shafts 5 and 9, is provided with a forward extension 38a to which a link 41' is pivotably attached.

Said link 41 at its lower end is articulated to a small lever 41a which freely pivots about the horizontal shaft 10 forming one of the axes of the two parallel linkage systems which are a characteristic feature of the machine.

The vertical arm 41 of the said angular support required in the first described embodiment shown in FIGS. 1 to 3 is omitted in the modified embodiment shown in FIGS. 4 and 5 and is replaced by the said link 41' which with the extension 38a of the arm 38 and the lever 41'a, forms a complementary parallel linkage in which said link 41' is displaced vertically along its longitudinal axis when both main parallel linkages are actuated by the lever 69 actuated in turn by lever 62. The advantage of this type of operation of the link 41' will be explained hereinafter.

In the embodiment shown in FIGS. 5 and 6, the machine includes accessories required to produce circular prints on flat articles. For this purpose, secured to link 41 is a bracket 71 on which is mounted a horizontal bar 72. Moreover, to the bracket member 48 and the crossbar 15 is secured a pedestal 73 provided at its end with a bearing 73a in which a vertical shaft 74 is rotatably and slidably held. This shaft carries at its lower end a gripping member 75 in which a slidable bar 76 may be secured; this bar carries a squeegee 44' adapted to engage a silk screen 17' when the shaft 74 is in lowered position. The screen 17 is mounted on a frame 16 carried by crossbar 15.

Secured on the upper part of shaft 74 are a drum 77 and a disc 78. Looped around the drum 77 is a wire cable 79 the ends of which are attached to the ends of bar 72. Disc 78 has a sufficiently large diameter to permit its resting upon the bar 72 when the latter is raised as will be described later.

Operation is quite simple: It is known that in fiat printing operations the screen generally remains stationary and the ink is discharged towards the surface to be printed on by the squeegee as it is moved while pressing against the screen. It is therefore necessary for the squeegee 44 to be rotated in order to produce the desired circular print. For this purpose the bar 72 is provided to form a driver bow for the drum 77. The drive is produced by sliding the carriage formed by arm 38 and lever 41'a along the shafts 5, 9 and 10. For this purpose the driver carriage 19 is connected with the arm 38 by means of stirrup 343535' and its vertically positioned spur 36 which engages the clevis 45 of sleeve 39 secured to the arm 38.

It is apparent that when the crank-disc 29 is rotated, it imparts rectilinear displacement through roller 26 to the carriage 19 and consequently to the bar 72. This movement is converted, by the action of the wire 79 Winding around drum 77, into a rotational movement imparted to the latter. The shaft 74 is thus driven in rotational movement during which the squeegee 44' describes a circular are or a complete circle over the silk screen 17 and thus produces the desired circular print.

As the carriage 19 reaches the end of its stroke, the camming crank-disc 29 acts on the lever 62 which, through rod 67, exerts a pull on the end of lever 69. The latter then rotates the shaft 5, thereby raising the shafts 9 and 10. The screen -17 therefore is lifted off the printing surface and simultaneously the link 41' and bracket 71 are also subjected to a vertical upward movement of greater amplitude than that of the movement of the screen. The bar 72 then engages the disc 78 and raises it, causing the shaft 74 to slide in the bearing 73a. The squeegee 44' is thus lifted ofi the screen and is able to pass over to the other side of the body of ink, thereafter to be returned in the reverse direction as, on bar 72 moving down again, the carriage 19 restores the arm 38 and link 41 to their initial positions.

It will be immediately understood that depending on the eccentric throw of roller 26 on crank-disc 29, a larger or smaller amplitude will be obtained for the stroke of the driver carriage 19, and that such stroke may thus represent part or all of the circumference of drum 77. The printing can therefore be effected upon annular sectors or on annular bands, such as the or plate.

What I claim is:

1. In a silk screen printing machine the improvement comprising in combination (a) a machine frame,

(b) an assembly of four parallel shafts forming the fulcrums of a parallelogrammatic linkage system including an upper rear or actuating shaft rotatably mounted in the frame, a lower rear or guide shaft fixedly mounted in the frame with its axis located in a vertical plane containing the axis of said upper rear shaft, two upper arms keyed to said actuating shaft, two lower arms pivoted on said guide shaft, an upper frontal shaft rotatably mounted in the outer ends of said upper arms, a lower frontal shaft rotatably mounted in the outer ends of said lower arms, and at least one vertical tie rod with its ends pivotably and slidably resting on said two front shafts,

(c) a first horizontal bar attached to the lower ends of said tie rods,

(d) a silk screen frame attached to said bar,

(e) a supporting member composed of a horizontal and a vertical arm, the outer end of the horizontal arm slidingly embracing the said upper rear shaft, the inner end of the horizontal arm slidingly embracing said upper frontal shaft, and a forked extension vertically depending from the outer end of said horizontal arm;

(f) a second horizontal bar fixedly mounted on said vertical arm of the supporting member,

(g) a squeegee carrier mounted on said second horizontal bar,

(h) driver carriage slidingly mounted on said lower rear shaft,

(i) actuating means imparting a reciprocating movement to said driver carriage,

(j) a two armed stirrup member with its arms rotatably mounted on said driver carriage and a spur thereupon, said spur when in upturned vertical position adapted to engage said forked extension, and thus to operatively connect said driver carriage with said second horizontal bar supporting the squeegee carr1er,

(k) a clevis member attached to said first horizontal bar and adapted to be engaged by said spur when in horizontal position and thus operatively connecting said driver carriage with said first horizontal bar supporting the screen frame,

(I) and actuating means adapted to pivot said upper rear shaft and actuate said parallelogrammatic linkage system.

2. In a silk screen printing machine according to claim 1, a driving carriage comprising a body slidingly embracing said lower rear shaft; a vertically extending guide groove on said body; a crank disk rotatably mounted in front of said guide groove; and a roller adjustably mounted on said disk and engaging said guide groove.

3. A silk screen printing machine according to claim 1 wherein said spur is provided with an oblong hole and retaining means on said clevis member adapted to engage said hole.

4. A silk screen printing machine according to claim 1 wherein the supporting member comprises a horizontal arm forwardly extended beyond the upper forward shaft, a vertical rod jointed with its upper end to the extended end of the horizontal arm, and a connecting link jointed with one end to the lower end of said vertical rod and with its other end to the lower forward shaft; said members forming a second parallelogrammatic linkage system; and supporting means for the squeegee carrier attached to said vertical rod.

5. A silk screen printing machine according to claim 2 wherein the actuating means for pivoting the upper rear shaft comprise a lever keyed on said shaft, a cammed marginal edge of a dish rim upon said dish, a roller cooperating with said cammed rim and an adjustable lever system transferring the movement of said rollerio said lever.

6. A silk screen printing machine according to claim 1 comprising a supporting member composed of a horizontal arm forwardly eittended beyond the upper forward shaft, a vertical rod jointed with its upper end to the extended end of the horizontal arm and a connecting link jointed with one end to the lower end of said vertical rod and with its other end to the lower forward shaft; said members forming a second parallelogrammatic linkage system; a pedestal mounted on the said first horizontal bar supporting the screen frame; a vertical shaft rotatably and slidably mounted in said pedestal; a pulley and a contact disk keyed to the upper portion of said shaft; a horizontal arm fixed to the lower portion of said shaft and adapted to hold the squeegee; a horizontal bar attached to said vertical rod; said contact disk adapted to be contacted and lifted by said bar; a wire or cable wound around said pulley with its free end attached to said bar whereby the transverse movement of the said support causes a rotational movement of the squeegee to eifect circular imprints on a flat object located below the screen.

References Cited in the file of this patent UNITED STATES PATENTS 2,152,356 Meyer et al Mar. 28, 1939 2,198,565 Schultz et a1. Apr. 23, 1940 2,209,688 Davis July 30, 1940 2,295,979 Van Gorden Sept. 15, 1942 2,301,119 Holbrook Nov. 3, 1942 2,492,052 Martin Dec. 20, 1949 

1. IN A SILK SCREEN PRINTING MACHINE THE IMPROVEMENT COMPRISING IN COMBINATION (A) A MACHINE FRAME, (B) AN ASSEMBLY OF FOUR PARALLEL SHAFTS FORMING THE FULCRUMS OF A PARALLELOGRAMMATIC LINKAGE SYSTEM INCLUDING AN UPPER REAR OR ACTUATING SHAFT ROTATABLY MOUNTED IN THE FRAME, A LOWER REAR OR GUIDE SHAFT FIXEDLY MOUNTED IN THE FRAME WITH ITS AXIS LOCATED IN A VERTICAL PLANE CONTAINING THE AXIS OF SAID UPPER REAR SHAFT, TWO UPPER ARMS KEYED TO SAID ACTUATING SHAFT, TWO LOWER ARMS PIVOTED ON SAID GUIDE SHAFT, AN UPPER FRONTAL SHAFT ROTATABLY MOUNTED IN THE OUTER ENDS OF SAID UPPER ARMS, A LOWER FRONTAL SHAFT ROTATABLY MOUNTED IN THE OUTER ENDS OF SAID LOWER ARMS, AND AT LEAST ONE VERTICAL TIE ROD WITH ITS ENDS PIVOTABLY AND SLIDABLY RESTING ON SAID TWO FRONT SHAFTS, (C) A FIRST HORIZONTAL BAR ATTACHED TO THE LOWER ENDS OF SAID TIE RODS, (D) A SILK SCREEN FRAME ATTACHED TO SAID BAR, (E) A SUPPORTING MEMBER COMPOSED OF A HORIZONTAL AND A VERTICAL ARM, THE OUTER END OF THE HORIZONTAL ARM SLIDINGLY EMBRACING THE SAID UPPER REAR SHAFT, THE INNER END OF THE HORIZONTAL ARM SLIDABLY EMBRACING SAID UPPER FRONTAL SHAFT, AND A FORKED EXTENSION VERTICALLY DEPENDING FROM THE OUTER END OF SAID HORIZONTAL ARM, (F) A SECOND HORIZONTAL BAR FIXEDLY MOUNTED ON SAID VERTICAL ARM OF THE SUPPORTING MEMBER, (G) A SQUEEGEE CARRIER MOUNTED ON SAID SECOND HORIZONTAL BAR, (H) DRIVE CARRIAGE SLIDINGLY MOUNTED ON SAID LOWER REAR SHAFT, (I) ACTUATING MEANS IMPARTING A RECIPROCATING MOVEMENT TO SAID DRIVER CARRIAGE, (J) A TWO ARMED STIRRUP MEMBER WITH ITS ARMS ROTATABLY MOUNTED ON SAID DRIVER CARRIAGE AND A SPUR THEREUPON, SAID SPUR WHEN IN UPTURNED VERTICAL POSITION ADAPTED TO ENGAGE SAID FORKED EXTENSION, AND THUS TO OPERATIVELY CONNECT SAID DRIVER CARRIAGE WITH SAID SECOND HORIZONTAL BAR SUPPORTING THE SQUEEGEE CARRIER, (K) A CLEVIS MEMBER ATTACHED TO SAID FIRST HORIZONTAL BAR AND ADAPTED TO BE ENGAGED BY SAID SPUR WHEN IN HORIZONTAL POSITION AND THUS OPERATIVELY CONNECTING SAID DRIVER CARRIAGE WITH SAID FIRST HORIZONTAL BAR SUPPORTING THE SCREEN FRAME, (I) AN ACTUATING MEANS ADAPTED TO PIVOT SAID UPPER REAR SHAFT AND ACTUATE SAID PARALLELOGRAMMATIC LINKAGE SYSTEM. 